DE2533322C2 - Cyanate-containing phenolic resins and their use for the production of molding compounds - Google Patents

Description

XX

R R

CH ₂

(I)

in which π has the value O or an integer of 1 or more and the radicals R are identical or different and denote hydrogen atoms or methyl groups, characterized in that the phenolic resins have a number average molecular weight of 350 to 700 and at least 50 wt. % Contain polymers of the formula (I) in which π is an integer from 1 to 3

2. Use of the phenolic resins containing cyanate groups according to claim 1 together with 20 to 8C wt .-% of a reinforcing material in powder or fiber form for the production of molding compounds.

3. Use of the compounds according to claim 1 together with 50 to 75% by weight of a reinforcing material in powder or fiber form for the production of molding compositions.

The invention relates to phenolic resins containing cyanate groups, comprising a mixture of polymers of the general formula (I)

OCN

OCN

OCN

CH ₂

(U

in which π has the value 0 or an integer of 1 or more and the radicals R are identical or different and denote hydrogen atoms or methyl groups, and their use for the production of molding compounds.

The production of cyanic acid esters by reacting aromatic, heterocyclic or aliphatic Hydroxyl compounds with halogen cyanides at temperatures up to 65 ° C in an inert, liquid medium in the presence of a base is known, for example, from CH-PS 4,39,243. As a hydroxyl compound is a phenol with, if appropriate, several phenolic OH groups is preferably used here

In GB-PS 10 87 009 and DE-AS 12 51 023 cyanate esters of phenolic resins and their Manufacture described. Here, a phenolic resin with a cyanide halide in water or an inert, Organic solvents reacted in the presence of a base. Novolaks with an average molecular weight of 600 to 1500 are used in particular as phenolic resins.

Finally, CH-PS 5 37 429 describes a process for the preparation of aromatic cyanic acid esters by reacting phenols with halocyanides according to the above-mentioned CH-PS 4 39 243, where as Phenolic resins soluble in organic solvents, in particular novolaks with an average molecular weight between 600 and 1500, are used.

It is thus already known to use phenolic novolaks with phenolic resins containing cyanate groups to produce an average molecular weight of 600 to 1500; cf. z. ö. also JA-AS 11712/70. However, cured products made from such phenolic resins have unsatisfactory properties, particularly with regard to thermal behavior.

The object of the invention is therefore to create phenolic resins which contain cyanate groups and which result in products with excellent properties, especially good thermal. Properties, let harden.

This object is achieved according to the invention by providing phenolic resins containing cyanate groups of the type mentioned at the outset, which are characterized in that the phenolic resins have a number average molecular weight of 350 to 700 and contain at least 50% by weight of polymers of the formula (I) where η is an integer from 1 to 3.

The number average molecular weight of the phenolic resins according to the invention is preferably 500 to 700, particularly preferably 550 to 650.

The phenolic resins containing cyanate groups according to the invention can be produced by a process in which which one a cyanide halide in an inert organic solvent in the presence of a base with a

Reacts phenol novolak from a mixture of polymers of the general formula (II).

OH

OH

in which η and R have the above meaning that contains at least 50% by weight of polymers of the formula (II) in which η is an integer from 1 to 3, the number average molecular weight of the phenol novolak at least 300 and at most 600, preferably 400 to 550, and in particular 440 to 530, is. In this reaction, the phenolic hydroxyl groups are practically completely converted into cyanate groups.

The phenolic resins according to the invention crosslink when heated and / or in the presence of a curing agent. Because of the high degree of crosslinking, the cured products have excellent properties, particularly good thermal properties, and have a glass transition point (glass transition temperature) of 300 ⁰ C or higher.

In the production of the phenolic resin according to the invention, it is important that a phenolic novolak is used from a mixture of polymers of the formula (H) which contains at least 50% by weight of polymers of the form! (II), in which π is an integer from 1 to 3. With a content of less than 50% by weight, the phenolic resin containing cyanate groups gives a cured product with poor thermal properties.

The phenolic novolak used to prepare the phenolic resins of the present invention can generally be used manufacture in the following way:

100 moles of at least one phenol, e.g. B. has the formula (III),

OH

(ΙΠ) 30

in which R has the above meaning. 70 to 90 mol of formaldehyde corresponding amount of formalin (37% CH ₂ O) and 0.1 to 1.0 mol of oxalic acid and / or an amount of hydrochloric acid corresponding to 0.05 to 0.5 mol of hydrogen chloride are added as a catalyst the hydrogen chloride are preferably used together. The phenols can be used either alone or in combination of two or more compounds. If several phenols are used, these can be mixed beforehand or added separately. The oxalic acid and / or hydrochloric acid can be added individually or as a mixture at the beginning or during the reaction. When heated, the reaction mixture initially emulsifies. The primary reaction is then carried out under reflux for 30 minutes to 5 hours. To carry out the secondary reaction, the reaction system is heated under a reduced pressure of 133 to 40 kPa for a further 2 to 8 hours with simultaneous separation of water and the unreacted components until the reaction system reaches a temperature of 110 to 170 ^° C. This results in a viscous synthetic resin melt that solidifies on cooling.

Examples of phenols of the formula (III) are phenol, cresol and xylenol.

The molecular weight distribution and the number average of the synthetic resin can be determined by gel permeation chromatography Determine (GPC) with tetrahydrofuran as solvent.

Suitable cyanide halides are, for. B. cyanogen chloride and cyanogen bromide, the former being preferred is added in an amount of 1 mole or more, preferably 1 to 2 moles, per mole of that in cyanate groups converting phenolic hydroxyl groups of the phenolic novolak used. When using less as 1 mole of cyanide halide, not all phenolic hydroxyl groups are converted into cyanate groups.

Suitable bases are, for. B. alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal carbonates, alkali metal carbonates, Alcoholates and tertiary amines. Specific examples of suitable bases are sodium hydroxide, Potassium hydroxide, calcium hydroxide, barium hydroxide, sodium bicarbonate, sodium carbonate, potassium carbonate, Lithium carbonate, sodium methylate, trimethylamine, triethylamine, tripropylamine and diethylcyclohexylamine. Of these, sodium hydroxide, potassium hydroxide and triethylamine are preferred. The base is used in a lot of 0.7 moles or more, preferably 1 to 2 moles, per mole of the phenolic to be converted into cyanate groups Hydroxyl groups of the phenol novolak are used. When using less than 0.7 moles of the base, the 6ö Reaction speed too slow.

Suitable inert organic solvents are, for. B. hydrocarbons, chlorinated hydrocarbons, nitro hydrocarbons, Ketones and ethers. Specific examples are benzene, toluene, xylene, chloroform, methylene chloride, Carbon tetrachloride, chlorobenzene, nitrobenzene, nitromethane, acetone, methyl ethyl ketone, methyl isobutyl ketone, Diethyl ether, tetrahydrofuran and dioxane. Of these are acetone, methyl ethyl ketone and dioxane preferred.

The process proceeds independently of the order in which the individual components are added to the reaction system, as long as the amount of base in the reaction mixture is less than that which is equivalent to the cyanide halide

is present In general, however, the phenolic novolak and cyanogen halide are dissolved in a solvent to which the base is then added dropwise with thorough stirring. The Reakticnstemperatur is preferably from -30 to +65 ⁰ C, in particular 0 to 20 ⁰ C. The phenolic resin is separated from the liberated from resulting salts of the reaction mixture characterized in that evaporating the solvent under reduced pressure or dripping, the reaction mixture in a solvent in which the phenolic resin is poorly soluble. The IR spectrum of the phenolic resin shows that the phenolic hydroxyl groups of the starting resin are practically completely converted into cyanate groups.

The phenolic resins according to the invention, containing cyanate groups, are suitable for numerous areas of application, z. B. for coating compounds, casting compounds, adhesives, laminates or molding compounds. For these purposes to are the phenolic resins either as such or in combination with other cyano esters, other polymers, Fillers, reinforcing materials and / or catalysts are used

Reinforced molding compositions are produced by mixing the phenolic resins according to the invention containing cyanate groups obtained with at least one powder or fibrous reinforcing material. Examples of powdery Reinforcement materials are powdered carbon black, quartz powder, baked clay, basic magnesium silicate Diatomaceous earth, aluminum oxide, calcium carbonate, magnesium carbonate, magnesia, kaolin and sericite examples for fibrous reinforcement materials are ceramic fibers, asbestos rock wool, glass fibers, slag wool, Carbon fibers and heat-resistant synthetic fibers such as polyimide fibers and aromatic polyamide fibers. These fibrous reinforcement materials can be in the form of fleeces, stacks, strands, webs, knotted or woven fabrics or nonwovens can be used. The reinforcement materials are in an amount of 20 to 80% by weight, preferably 50 to 75% by weight, based on the weight of the Molding compound, used

The reinforced molding compounds produced using the phenolic resins according to the invention are Superior to conventional molding compounds based on phenolic resins containing cyanate groups in the following respects:

Since the reinforced molding compounds produced by means of the phenolic resins according to the invention ^{soften at 130 to 200 °} C., they can already be deformed in this temperature range under a pressure of 9.8 to 98 bar, in particular 19.6 to 68.6 bar. The flow properties of the molding material are retained during kneading, since there is no premature gelation of the resin component of the obtained from the reinforced molding compositions by heating in the presence or absence of a curing catalyst, cured products have a distortion temperature of 300 ⁰ C or higher and a glass transition point of 300 ⁰ C or higher so that they are excellent in heat resistance. In addition, the cured product shows excellent electrical properties, e.g. B. high insulation resistance and arc resistance, as well as good appearance and excellent surface smoothness.

Suitable curing catalysts are, for. B. Chlorides, such as aluminum chloride, tin chloride and zinc chloride,

Amines, such as triethylenediamine and dimethylbenzylamine, imidazoles, such as 2-methylimidazole and 2-methyl-4-ethylimidazole, Phenols such as phenol and pyrocatechol, metal salts of organic acids such as zinc octoate and titanium butyrate and metal chelates, such as bis-acetylacetonato-zinc. Bis-acetylacetonato-kupferfll) and tris-acetylacetonato-iron (IH).

In addition to the reinforcing materials, the molding compositions can also contain lubricants, e.g. B. higher fatty acids, such as Stearic acid, or its amides, calcium salts, magnesium salts or zinc salts, inorganic pigments, such as Titanium oxide, lead yellow, iron black, molybdenum red, Prussian blue, ultramarine, cadmium gel and cadmium red organic pigments and dyes such as phthalocyanine, resins such as rosin, shellac, copal resin, Phenolic resins, urea resins, melamine resins, epoxy resins, imide resins, alkyd resins, polyester resins and others Contain cyano ester resins, flame retardants and fire retardants.

The examples illustrate the invention. All parts and percentages are by weight unless otherwise specified. The molecular weight is given in the examples as a number average, as determined by gel permeation chromatography (GPC) has been determined with tetrahydrofuran as the solvent

example 1
(Manufacturing example)

A mixture of 160 g (1.70 mol) phenol and 100 g (1.23 mol CH ₂ O) 3 /% formalin are mixed with 0.80 g (0.00i> 9 mol) oxalic acid and 0.3 g ( 0.0029 Mo! HCl) 35% hydrochloric acid as catalysts added to the mixture of an emulsion 99 is heated to 100 ⁰ C to form, then held 80 minutes at reflux and then dehydrated under reduced pressure and the resulting phenol (62 to 68 F. ° C) contains 16%

unreacted phenol and a polymer of the formula (II) with n = 0.75% - polymers with π - 1.2 or 3 and 9% polymers with π £ 4 and has a number average of 380.

42 g (0396 mol as -OH) of the phenol novolak obtained are dissolved in 210 ml of methyl ethyl ketone. The cooled to 0 ° C solution is then treated with 46 g (0.434 mole) of cyanogen bromide was added with well stirring 42 g (0.415 mol) of triethylamine are added dropwise, followed by holding the Reaktionstcmperatur at 5 to 1O ⁰ C. After the reaction has ended, the triethylammonium bromide formed as a by-product is filtered off with suction. The filtrate is concentrated under reduced pressure, a solid phenolic resin containing cyanate groups (F. 45 to 52 ⁰ C) with a number average of 480, which is soluble in methyl ethyl ketone. The phenolic resin contains 15% of the mononuclear compound and a polymer of the formula (I) with π = 0.76% polymers with / 7 = 1.2 or 3 and 9% polymers with η £ 4.

In the IR specfum, the absorption of the phenolic hydroxyl groups has disappeared at about 3400 cm- ' and for this, the absorption typical of cyanate groups occurs at 2250 cm- '. This suggests that practically all hydroxyl groups are converted into cyanate groups.

This is done by melt pressing the phenolic resin obtained at 50 ° C and then curing at 200 ° C produced hardened product far a glass point above 300 ° C, as the measurement of the thermal Expansion coefficient results.

Example 2 s

(Manufacturing example)

The procedure of Example 1 is repeated, but 27 g (0.439 mol) of cyanogen chloride are used instead of Rxomcyan used. A synthetic resin similar to that in Example 1 with a glass point above is obtained 300 ° C. ίο

Example 3
(Production example)

A mixture of 150 g (1.59 mol) phenol and HOg (136 MoI as CH ₂ O) 37% formalin is mixed with 0.75 g (0.0083 mol) oxalic acid and 03 g (0.0029 mol as HCl) 35% hydrochloric acid added as catalysts. The mixture is heated to 99-100 ° C to form an emulsion. The emulsion is then refluxed for 75 minutes and then dehydrated under reduced pressure. The solid Phenoinovoiak obtained (mp 85 to 93 ° C) contains 11% unreacted phenol and a polymer of the formula (II) with η = 0.64% polymers with π = 1.2 or 3 and 25% polymers with / j_4 and has a number average of 430.

The phenol novolak obtained is cyanated according to Example 1. After the triethylamine salt has been filtered off, the reaction mixture is added dropwise to vigorously stirred water, a phenolic resin containing cyanate groups being obtained in powder form. After drying, the synthetic resin powder has a melting point of 63 to 67 ° C and a number average of 540. The phenolic resin contains 64% of polymers of the formula (I) with / J = 1,2 or 3 (determined by GPC). In the IR spectrum, a strong absorption at 2250 cm- 'indicates that the phenolic hydroxyl groups are practically completely converted into cyanate groups. The cured product has a glass transition point above 300 ⁰ C.

Example 4
(Manufacturing example)

A mixture of 108 g (0.999 mol) m-cresol and 65 g (0.801 mol as CH ₂ O) 37% formalin is mixed with 0.2 g (0.0022 mol) oxalic acid and 0.1 g (0.0010 mol as HCl) 35% hydrochloric acid added as catalysts. The mixture is heated to 99-100 ° C to form an emulsion. The emulsion is _{then refluxed for 4V for 2} hours and then dehydrated under reduced pressure. {!!) with B = !, 2 or 3 and has a number in the middle! from 550 to.

72 g (0.6 mol as —OH) of the m-cresonovolak obtained are dissolved in 210 ml of acetone. The solution, cooled to 0 ° C., is then treated with 70 g (0.661 mol) of cyanogen bromide and then with 64 g (0.632 mol) of triethylamine dropwise. After the reaction has ended, the triethylammonium bromide is separated off The synthetic resin contains 64% polymers of the formula (I) with π = 1, 2 or 3 and has a number average of 640. In the IR spectrum, a strong absorption at 2250 cm- 'indicates that the phenolic hydroxyl groups are practically completely converted into cyanate groups. The glass point of the hardened molding is above 300 ° C.

Example 5
(Production example)

A mixture of 122 g (0.999 mol) 3,5-xylenol and 61 g (0.752 mol as CH ₂ O) 37% formalin is mixed with 0.16 g (0.0018 mol) oxalic acid and 0.1 g (0 , 0010 MoI as HCI) 35% hydrochloric acid added as catalysts. The mixture is heated to 990 ° C. to form an emulsion. The emulsion is then reacted for 2 hours at 90 ° C. and then dehydrated under a pressure of 8 kPa until the temperature reaches a value of 160.degree. C. The solid xylenol novolak obtained (mp 90 to 98.degree. C.) contains 72% polymers of the formula (II) with / 7 = 1, 2 or 3 and has a number average of 520.

67 g (03 mol as —OH) of the xylenol novolak obtained are dissolved in 250 ml of acetone. The solution, cooled to 0 ° C., is then mixed with 34 g (0.553 mol) of cyanogen chloride and then with 53 g (0.524 mol) of triethylamine dropwise. After the reaction has ended the resulting triethylammonium chloride is filtered off. The reaction mixture obtained is poured into vigorously stirred water, a powdery synthetic resin (temperature 68 to 77 ° C) being obtained Hydroxyl groups are practically completely converted into cyanate groups. The cured molded article has a glass transition point of 260 ⁰ C.

Example! 6th
(Production example)

A mixture of 47 g (0.499 mol) phenol and 69 g (0350 mol as CH ₂ O) 37% formalin is mixed with 036 g (0.0040 mol) oxalic acid and 0.1 g (0.0010 mol as HQ) 35 % hydrochloric acid added as a catalyst

Mixture is heated under emulsification and to 99 to 10O ⁰ C for 30 minutes held at reflux, followed by 54 g (0.499 mol) of m-cresol is added, and the reaction is carried out for a further 30 minutes under reflux. The reaction mixture is dehydrated under a pressure of 8 kPa until a temperature of 160 ^° C. is reached. The solid phenol novolak obtained (melting point 85 to 91 ° C.) contains 66% of polymers of the formula (H) with n- 1, 2 or 3 and has a number average of 490.

45 g (0398 mol as -OH) of the phenol novolak obtained are dissolved in 250 ml of methyl ethyl ketone. The solution, cooled to ^ C , is then mixed with 47 g (0.444 mol) of cyanogen bromide and then with 43 g (0.425 mol) of tilethylamine dropwise. F. 53 to 65 ^° C.) is obtained. In the IR spectrum of the synthetic resin, a strong absorption at 2250 cm- 'indicates that the phenolic hydroxyl groups are practically completely converted into cyanate groups. The glass transition temperature of the cured molding is above 30O ⁰ C.

Example 7
(Manufacturing example)

In 250 ml of methyl ethyl ketone, 21 g (0.198 mol as -OH) of the phenol novolak U obtained in Example 1

and 24 g (0.20 Mo!) of the m-cresol novolak obtained in Example 4 dissolved. The solution cooled to O ⁰ C |]

47 g (0.444 mol) of cyanogen bromide and then 43 g (0.425 mol) of triethylamine are then added dropwise. 1

After the reaction has ended, the triethylammonium bromide formed is filtered off and the reaction mixture ■ -;

Mixture concentrated under reduced pressure, a solid synthetic resin (mp 49 to 61 ° C) is obtained. In the IR spectrum | .f!

of the resin, a starch absorption at 2250 cm- 'indicates that the phenolic hydroxyl groups pi

are practically completely converted into cyanate groups. The glass point of the hardened molding is f}

above 300 ° C. '■ {;

1

Examples | <

(Production example) 'ü

A solution of 42 g (0.396 mol as -OH) of the phenol novolak obtained in Example 3 is dissolved in 210 ml of f _t

Dissolved dioxane. The at 0 ⁰ C abgekühlte'Lösung is then treated with 46 g (0.434 mole) of cyanogen bromide. The obtained | i

16.4 g (0.41 mol) of powdered sodium hydroxide are gradually added to the mixture with vigorous stirring, U

the reaction temperature being kept at 5 to 10 ^° C. The reaction product shows practically the same |!

Properties like the phenolic resin containing cyanate groups obtained in Example 3. The I made from it, too

cured molded body has the same properties as the molded body from example 3. |

£

Comparative Example 1 I.

To 1,880 g (19.98 mol) at 90 ⁰ C over 2 hours phenol are heated in 1265 g (15.59 MoI as CH ₂ O) Ii 37% formalin and 50 g (0.555 mol) of oxalic acid was added dropwise Then, the reaction 8 Hours at 90 ⁰ C Üj

performed Then cool the reaction mixture to 4O ⁰ C., the aqueous phase is separated, washed Wed :. f | 300 ml of hot water and dehydrated under a pressure of 5.3 kPa, to a temperature of 16O ⁰ C reaches | j This method is, in "Methoden der organischen Chemie", Vol 14/2, p 273, Example 2. Fig. described. The solid phenol novolak obtained has a softening point of 124 ° C and contains 3% unreacted oil! Phenol and a polymer of the formula (II) with / 7 = 0.23% polymers with n = \, 2 or 3 and 74% polymers with Jj

η ä 4. The average molecular weight (number average) is 850.

The phenol novolak obtained is cyanated according to Example 1, resulting in a powdery synthetic resin which has no specific melting point and a number average of 1050. The synthetic resin contains 25% polymers of the formula (I) with n £ 3 and 75% polymers with n> 4. Although there is strong absorption at 2250 cm- 'in the IR spectrum, bands can also be observed which indicate residual phenolic hydroxyl groups in the synthetic resin. A hardened molded body made from the synthetic resin has a glass point of 248 ° C.

Comparative example 2

A mixture of 180 g (1,313 mole) of phenol and 90 g (1.109 mol as CH ₂ O) 37% formalin is added with 036 g (0.011 MoI) of oxalic acid as a catalyst, followed by heating the reaction mixture to emulsify at 80 ⁰ C. The emulsion is then reacted for 30 minutes at 80 ⁰ C, and finally dehydrated under reduced pressure at 100 ⁰ C, until a pressure of 4 kPa reaches the phenol obtained at room temperature He semi-solid contains 62% of unreacted phenol and a polymer of formula (II ) with n = 0.37% polymers with n = 1, 2 or 3 and 1% polymers with λ!> 4 and has a number average of 220.

The phenol obtained is cyanated according to Example 1, wherein a semi-solid cyanatgruppenhaltiges phenolic resin produced in the IR spectrum of the resin vanish attributable to the phenolic hydroxyl absorption and there is a strong absorption at 2250 cm ^-1. A cured molded body made from the synthetic resin has a glass point of 225 ° C., as can be seen from the measurement of the coefficient of thermal expansion

Comparative example 3

Equal amounts of the phenol novolaks from Comparative Examples 1 and 2 are dissolved in methyl ethyl ketone solved. Mathematically, the mixed phenol novolak should contain 32.5% unreacted phenol and a polymer Formula (II) with / 7 = 0, contain 30% polymers with / J = I, 2 or 3 and 37.5% polymers with Na4 and a Have a number average of 350.

The mixed phenol novolak is cyanated according to Example 1, a phenolic resin containing cyanate groups (F. 42 to 56 ° C) is obtained. A cured molded body made from the phenolic resin has a glass transition point of 242 ° C, as can be seen from the measurement of the thermal expansion coefficient.

Comparative example 4

The same amounts of the phenol novolaks from Example 1 and Comparative Example 3 are dissolved in methyl ethyl ketone. Mathematically, the mixed phenol novolak should contain 39% unreacted phenol and polymer of the formula (II) with π = 0.56% polymers with η = 1.2 or 3 and 5% polymers with η ä4 and have a number average of 280.

The mixed phenol novolak is cyanated according to Example 1, a phenolic resin containing cyanate groups (melting point 31 to 43 °) being obtained. A cured molded body made from this phenolic resin has a glass point of 247 ° C suf, as can be seen from the Mcssun ^{0 of} the coefficient of thermal expansion.

Of Comparative Examples 1 to 4 show that using one of the following Phenolnovobke hardened molded body with a glass point below 25O ⁰ C and thus a correspondingly poorer heat resistance than the inventive molding body arise:

- Phenol novolaks which contain less than 50% by weight of polymers of the formula (II) with / 7-1,2 or 3 and a have a number average molecular weight of less than 300 or more than 600,

- Phenol novolaks which contain less than 50% by weight of polymers of the formula (II)

n = 1, 2 or 3 and have a number average molecular weight of at least 300 and less than 600, and

Phenol novolaks which contain more than 50% by weight of polymers of the formula (II) with n = 1, 2 or 3 and have a number average molecular weight of less than 300 or more than 600.

Comparative example 5

40 g (0.40 mol as -OH) of bishydroxybisphenylmethane are dissolved in 200 ml of acetone. The cooled to 0 ° C solution is then treated with 46 g (0.434 mole) of cyanogen bromide and then with good stirring dropwise with 42 g (0.415 mol) of triethylamine The reaction temperature is maintained at 5 to 10 ⁰ C. After the reaction, filtering the by-products formed, the filtrate is concentrated and cooled to give crystalline Biscyanato-bisphenylmethan deposited in the IR spectrum, a strong absorption at 2250 cm- ¹ indicates that the phenolic hydroxyl groups practically completely converted into cyanato are. The glass point of a hardened shaped body produced on it is 194 ° C.

Test results

The following table shows the moduli of elasticity measured at room temperature and 250 ° C., which are a measure of the mechanical strength at high temperatures. The dynamic viscoelasticity of the cyano group-containing phenolic resins from Examples 1 to 7 and Comparative Examples 1 and 5 is determined in each case. The moduli of elasticity are determined by the phase difference method (frequency 11 Hz). In the case of the values given, a higher dynamic storage modulus (E ') or a lower dynamic loss modulus (E ") mean better mechanical strength.

Tabel

dynamic storage module E '
(dyn / cm ² )
Room temperature 250 ° C 1.6x10 '"
1.6x10 '°
15x10 '°
13x10 '°
1.6 10 '°
1.6 XlO ¹⁰ dynamic loss module E "
(dyn / cm ² )
Room temperature 250 ^° C 4,4x10 «
43x10 «
3.0x10 "
4.8x10 «
8.6x10 "
45x10 "
45x10 " Example)
1
2
3
4th
5
6th
7th K) K) K) K) K) N) K)
ίο to "- ίο ίο Io ίο
XXXXXXX
O O O O O O O 23x10 «
23x10 «
2.4 χ 10 «
2.9x10 «
23x10 «
2.8 χ 10 "
2.7 χ 10 « Comparison
example
1
5 1.2 χ 10 '°
1.1 xlO ¹⁰ 12xi0 «
15x10 « 2 ^ x10 '°
2.1x10 '" 3.1 χ 10 «
35x10 "

10

25 30

40 45 50 55 60 65

Example 9 (Usage example)

30 parts of the phenolic resin from Example 1 containing cyanate groups are mixed with 70 parts of quartz powder, 0.5 parts 5 calcium stearate, 0.2 parts carbon black and Oi parts 2-methylimidazole are added and mixed thoroughly. The received Mixture is kneaded for 3 to 5 minutes at 60 to 70 ° C, whereby a uniform mixture is formed which quickly is cooled and ground. The molding compound obtained is at 150 to 160 ° C under a pressure of 68.6 bar pressed and then heat-treated for 2 hours at 200 ° C. The molded body obtained has the following Characteristics: to

Glass point > 300 ° C Flexural strength 10 kg / mm ² Insulation resistance 5χ10 ¹⁵ Ω Arc resistance 220 sec

The flow properties of the molding compound are determined according to the test standard EMMI 1-66 (The Society of the Plastics Industry, Inc, Epoxy Molding Material Institute). The molding compound shows an EMMI spiral flow of 75 cm (for materials for low pressure deformation, an EMMI spiral flow of 30 cm or more is required).

20 Example 10

(Application example!)

A mixture of 30 parts of the phenolic resin used in Example 9, 35 parts of glass fibers and 35 parts Quartz powder is mixed with 0.5 part of calcium stearate, 0.2 part of carbon black and 0.2 part of 2-methylimidazole. That 25 mixture obtained is processed according to Example 9 to form a molding composition, which is then cured and is heat treated. The molded body obtained has the following properties:

Glass point> 300 ° C Flexural strength 13 kg / mm ²

30 Insulation resistance ^{2χ10 Ι5} Ω

EMMI spiral flow 65 cm

Example 11 (Usage example)

Using the phenolic resin containing cyanate groups from Example 3, a molding compound having the composition of Example! 9 produced By curing and heat treating the molding compound, one obtains a Moldings with the following properties:

40 glass point> 300 ° C

Flexural strength 10 kg / mm ² Insulation resistance 5 χ 10 ¹⁵ Ω Arc resistance 220 see EMMI spiral flow 45 cm

Example 12 (Usage example)

A mixture of 30 parts of the phenolic resin containing cyanate groups from Example 4 and 70 parts of quartz powder 50 is mixed with 0.5 part of calcium stearate, 0.2 part of carbon black and 0.4 part of 2-methylimidazole Mixture is processed according to Example 9 to form a molding compound, which is then cured and heat-treated is obtained, a molding is obtained with the following properties:

Glass point > 300 ° C Flexural strength 10 kg / mm ² Insulation resistance 2 x 10 ¹⁵ Ω Arc resistance 210 sec EMMI spiral flow 40 cm

Example 13 (Usage example)

A mixture of 30 parts of the phenolic resin containing eyanate groups from Comparative Example 1 and 70 parts of quartz powder is mixed with 0.5 part of caldum stearate, 0.2 part of carbon black and 0.2 part of 2-methylimidazole and mixed thoroughly. The mixture obtained is for 3 to 5 minutes 120 kneaded to 130 ° C to form a mass which is then pressed at 150 to 160 ⁰ C under a pressure of 196 bar and then heat-treated for 2 hours at 200 ⁰ C. The result is a shaped body with the following properties:

Gias point 260 ⁰ C 10 Flexural strength 10 kg / mm ^{2 Insulation resistance} 2 χ 10 Iä Ω Arc resistance 220 see EMMI spiral flow 10 cm Comparative example 6

g 2,2'-bis (4-cyanatophenyl) propane, which was melted by heating to 120 ⁰ C, with 0.2 g 2-methyl-4-ethylimidazole added The mixture is reacted for 5 hours at 120 ⁰ C, whereby a synthetic resin (F. 55 to CO ⁰ C) is obtained. This is processed according to Example 9 to form a molding compound which is then cured and heat-treated. A molded body is produced with the following properties:

Glass point 190 ⁰ C Flexural strength 10 kg / mm ² Insulation resistance 4 xlO ¹⁵ Ω Arc resistance 188 sec EMMI spiral flow 80 cm

Claims (1)

Patent claims: 1. Phenolic resins containing cyanate groups, comprising a mixture of polymers of the general formula (I) OCN CH ₂ OCN OCN